1. Field of the Invention
The present invention generally relates to phototherapy devices. More specifically, it relates to phototherapy devices comprising semiconductor nanoparticles (“quantum dots”) that adjust the light used to certain wavelength(s).
2. Description of the Related Art including information disclosed under 37 CFR 1.97 and 1.98
The term phototherapy literally means the use of light to treat medical conditions. It is used to treat common skin conditions such as psoriasis, atopic eczema, acne, and the like. Other common names include: light boxes, bright light treatment, ultraviolet light therapy, UV, ultraviolet blood irradiation, colored light therapy, chromatotherapy. Within the scientific and medical communities, phototherapy is also referred to as ultraviolet phototherapy, photopheresis, extracorporeal photochemotherapy, and photodynamic therapy.
Light therapy involves the use of visible light or non-visible ultraviolet light to treat a variety of conditions.
Medical professionals may prescribe the use of light boxes, photopheresis, photodynamic therapy, or UV light therapy. These are typically used to treat conditions for which studies have shown the methods to be safe and effective. For example, the use of light boxes to mimic sunlight is a proven medical treatment for seasonal affective disorder (SAD). Ultraviolet (UV) light therapy is used to treat psoriasis and cutaneous T-cell lymphoma (a type of cancer that first appears on the skin). Photodynamic therapy is helpful in treating certain cancers or precancers of the skin, esophagus, and lungs, and is now being tested against other types of cancer. A special form of UV blood irradiation, called photopheresis or extracorporeal photochemotherapy, also inhibits T-cell lymphoma and may be helpful for other conditions.
Colored light therapy involves the use of colored lights such as blue, red, and violet lights that the practitioner shines directly on the patient. In some cases, the patient purchases the device and uses it at home in this alternative use of light therapy. Sometimes the lights flash in patterns.
One type of light therapy is used in conventional medicine for newborns who have a buildup of a waste product called bilirubin in the blood. The infant's skin is exposed to a special blue light, usually for several days. This helps the bilirubin to break down into a substance that is easier for the baby to excrete.
Light boxes contain lights that simulate the wavelengths of sunlight, and are used in mainstream medicine. Patients getting this kind of treatment sit in front of the light box or special bright lamp for a prescribed amount of time each day. The person may read or do other tasks during the light exposure, but must sit close enough to the light to receive its full effect. The amount of time required will vary according to the person and the strength of light being used. For most people with SAD, light treatment is used early in the morning from thirty minutes to two hours each day. A brighter light may require less time exposure.
In ultraviolet light therapy, the eyes and unaffected skin are protected while the patient is exposed to UV light for a prescribed length of time. This conventional treatment for psoriasis may involve the use of UV light and drugs that make the skin sensitive to UV light. A newer type of UV light source, called narrow-band UV light, is also being used now and may be preferred over broad-band UV light.
Ultraviolet blood irradiation is called photopheresis or extracorporeal photochemotherapy in conventional medicine and is mainly used to inhibit T-cell lymphoma. It may also be helpful for other conditions. During this procedure, blood is removed from the patient and separated into different types of cells. About a pint of blood, mostly white blood cells, is treated with a special drug to make it make it more sensitive to light. It is then treated with UV light, and the blood is infused back into the patient. This procedure is considered a form of immunotherapy and takes from three to five hours.
Photodynamic therapy is used in conventional medicine for certain types of cancer. The patient is given a drug to make cancer cells more sensitive to light. The tumor area is then exposed to laser or another type of light.
Ultraviolet light therapy (phototherapy) is commonly used to treat psoriasis. There is also evidence that UV light therapy inhibits the growth of cutaneous T-cell lymphoma (a type of skin lymphoma). Researchers have found that when used along with other treatment, it has resulted in long-term remission and cure among many patients in the early stage of the disease. In patients who were treated later in the disease, it has prolonged survival. Early studies suggest that certain types of UV light may also be helpful for people with atopic dermatitis (an allergic skin condition) and vitiligo (uneven pigment in the skin).
Ultraviolet blood irradiation treatment is approved by the U.S. Food and Drug Administration (FDA) for treating T-cell lymphoma involving the skin. Photopheresis is sometimes used conventionally when organ transplant rejection or graft-versus-host disease (a complication related to bone marrow or stem cell transplants) does not respond to usual conventional treatments. Some clinical trial results appear promising for the treatment of immune system diseases such as multiple sclerosis, systemic sclerosis, rheumatoid arthritis, lupus, and type 1 diabetes.
Light therapy that involves only visible light (light boxes and colored light therapy) is generally considered safe. Any treatment that exposes the patient to ultraviolet radiation presents some danger, including premature aging of the skin and an increased risk for skin cancer later in life.
People who get long-term UV light treatment for psoriasis or other conditions may have a greater-than-average number of cataracts and skin-related problems, including cancer. They may also be at higher risk of sunburn the day of UV treatment and are advised to avoid natural sunlight.
A flexible organic light emitting diode (FOLED) is a type of organic light-emitting diode (OLED) incorporating a flexible plastic substrate on which the electroluminescent organic semiconductor is deposited. This enables the device to be bent or rolled while still operating. Flexible OLEDs form the basis of one method of fabricating a rollable display.
An OLED emits light due to the electroluminescence of thin films of organic semiconductors approximately 100 nm thick. Regular OLEDs are usually fabricated on a glass substrate, but by replacing glass with a flexible plastic such as polyethylene terephthalate (PET) among others, OLEDs can be made both bendable and lightweight.
Such materials may not be suitable for comparable devices based on inorganic semiconductors due to the need for lattice matching and the high temperature fabrication procedure involved.
In contrast, flexible OLED devices can be fabricated by deposition of the organic layer onto the substrate using a method derived from inkjet printing, allowing the inexpensive and roll-to-roll fabrication of printed electronics.
Flexible OLEDs may be used in the production of rollable displays, electronic paper, or bendable displays which can be integrated into clothing, wallpaper or other curved surfaces. Prototype displays have been exhibited that are capable of being rolled around the width of a pencil.
Current phototherapy masks are limited by:                Available area to populate with LED's        Fixed wavelengths        Varying distance across areas of the face        Distance from user's skin required for even distribution of light and alters light delivery        Variability of peak wavelength        Cost can be prohibitive        Performance trade-off between professional (clinical) and home-use devices        